Conventionally, as shown in FIG. 35, a left-handed filter of this kind has been constituted by forming on a dielectric layer a so-called left-handed transmission line in which a plurality of inductors 4 and capacitors 3 connected to the ground are alternately connected together, and input and output coupling elements 30a and 30b are connected at both ends. For example, a Patent Document 1 listed below has been known as prior art document information about the present application.
Patent Document 1: Specification of U.S. Patent Application Publication No. US 2006/0066422 A1.